Vaccination in twin pregnancies: comparison between immunization before conception and during pregnancy.

To evaluate the development of neutralizing Anti-Spike Protein IgG (Anti-S-IgG) during twin pregnancies before conception vs. during pregnancy. In this prospective study, three blood samples were collected from pregnant women and subjected to anti-S-IgG immunodiagnostics. The patient's medical records, including vaccination and PCR test results, were collected from the hospital's electronic database. Age-matched non-pregnant women were used as a control group. We enrolled 83 women with twin pregnancies. 49 women were vaccinated before conception, 21 women were vaccinated during pregnancy, and 13 were not vaccinated. Of the 13 women who weren't vaccinated, three became positive during pregnancy, and all three were severely ill. By contrast, in women who were vaccinated during or before pregnancy, COVID-19 infection during pregnancy caused only mild symptoms. A ten-fold lower level of neutralizing Anti-S-IgG in the 3rd trimester was observed in healthy women who were vaccinated before conception and remained healthy until discharge from the hospital after delivery 1605 (IQR: 763-2410) compared to the healthy women who were vaccinated during pregnancy 152 AU/mL (IQR: 54-360). This difference was higher among women who were infected by COVID-19 (as verified by a positive PCR test). The third-trimester level of neutralizing Ant-S-IgG in the infected group was 4770 AU/mL (4760-6100) in infected women vaccinated before conception compared to those vaccinated during pregnancy who had 70 AU/mL (IQR: 20-170) (p < 0.001). In women vaccinated at 13-16 weeks gestation, neutralizing Anti-S-IgG at 20-22 weeks went up to 372 AU/mL (IQR: 120-1598) but rapidly dropped to 112 AU/mL (IQR: 54-357) at 28-30 weeks, (p < 0.001), a faster decline than in women vaccinated at a median 22 weeks before conception. Being infected by COVID-19 before conception was linked to having low Anti-S-IgG levels during pregnancy, whereas being infected by COVID-19 during pregnancy led to a very high response in the 3rd trimester. In twin pregnancies, significantly lower neutralizing Anti-S-IgG levels were observed in women vaccinated during pregnancy compared to those vaccinated before conception, whether infected or not infected by COVID-19. A full course of vaccination before conception is recommended.Trial registration. ClinicalTrials.gov Protocol Registration and Results System (PRS) Receipt Release Date: October 4, 2021. https://clinicaltrials.gov/ ID: NCT04595214.

Peri-implantation cytokine profile differs between singleton and twin IVF pregnancies.

PROBLEM: It is unknown whether maternal cytokine production differs between twin and singleton gestations in the implantation phase. A difference in maternal serum cytokine concentrations in twins would imply a dose-response to the invading embryos, as opposed to a general immune reaction. METHOD OF STUDY: A prospective longitudinal cohort of women aged 18-45 at an academic fertility center undergoing in vitro fertilization and embryo transfer (IVF-ET) underwent routine collection of serial serum samples starting 9 days after ET and then approximately every 48 hours thereafter. Cryopreserved aliquots of these samples were assayed for interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and C-X-C motif chemokine ligand 10 (CXCL10) using the SimplePlex immunoassay platform. Pregnancies were followed until delivery. Serial measures of serum concentrations of IL-10, CXCL10, and TNF-α in singleton or di-di twin pregnancies from 9 to 15 days after IVF-ET were compared. RESULTS: Maternal serum levels of CXCL10 are significantly lower in women with di-di twin pregnancies in early implantation compared to those with singleton gestation (day 9-11, P = .02). Serum levels of TNF-α and IL-10 were comparable at all studied time points (P > .05). CONCLUSION: Maternal serum levels of CXCL10 are significantly lower in the earliest implantation phase in di-di twins compared to singleton conceptions. Given the known anti-angiogenic role of CXCL10, we hypothesize that lower CXCL10 levels in twin implantations allow an environment that is conducive for the greater vascularization required for the establishment of dual placentation in di-di twins.

Maternal serum screening marker levels in twin pregnancies affected by gestational diabetes.

PURPOSE: To investigate the levels of maternal serum screening markers in the first and second trimester twin pregnancies, which subsequently developed gestational diabetes mellitus (GDM). METHODS: 145 twin pregnancies were recruited in the first trimester. Stored blood samples were retrospectively tested for pregnancy-associated plasma protein (PAPP)-A, human chorionic gonadotrophin (hCG), placental growth factor (PlGF), placental protein (PP)13, α-fetoprotein (aFP) and inhibin A. Values were expressed in multiples of the gestation-specific median (MoMs) in singletons, adjusted for maternal weight and parity, as appropriate. RESULTS: Twenty samples of first and second trimester were available from 11 twins who subsequently developed GDM and 219 samples from unaffected twins. The median PAPP-A level in the affected twins was 3.61 MoM compared with 2.46 MoM in unaffected twins (P < 0.001, Wilcoxon rank sum test, two tailed); significant results were found in both trimesters. The median PP13 was also increased but to a lesser extent. It was only statistically significant overall (P < 0.05) and in second trimester samples (P < 0.02). No other marker differed significantly. Logistic regression found that combining PAPP-A and maternal weight had a 55% detection rate for a 10% false-positive rate. CONCLUSIONS: Early prenatal marker evaluation in twin pregnancies can be also useful for predicting the risk for developing GDM and should be further investigated.

Analysis of false-positive results of fetal RHD typing in a national screening program reveals vanishing twins as potential cause for discrepancy.

OBJECTIVES: We aim to elucidate causes of false-positive fetal RHD screening results obtained with cell-free DNA. METHODS: Fetal RHD screening was performed in 32,222 samples from RhD-negative women by multiplex real-time PCR in triplicate for RHD exons 5 and 7 using cell-free DNA isolated from maternal plasma obtained in the 27th gestational week. PCR results were compared with cord blood serology in 25,789 pregnancies (80.04%). False-positive cases were analyzed. Known biological causes (RHD variant genes), technical causes of discordance, and errors around blood sampling were investigated with leukocyte DNA from maternal and cord blood, and cell-free DNA from stored maternal plasma. RESULTS: Not only RHD but also Y-chromosome (DYS14) sequences were present in four plasma samples from RHD-negative women bearing an RHD-negative girl. Sample mix-up and other sampling errors could be excluded in three samples. CONCLUSIONS: These results indicate that false-positive fetal RHD screening results can be caused by cell-free DNA fragments in maternal plasma derived from a third cell line that is not representative for either the maternal genome or the genome of the vital fetus. We propose that remaining (cyto)trophoblasts of a vanishing twin are the underlying mechanism, and we estimate a frequency of this phenomenon of 0.6%.

Placental transfer of IgG antibodies specific to Klebsiella and Pseudomonas LPS and to group B Streptococcus in twin pregnancies.

Group B Streptococcus (GBS), Klebsiella spp. and Pseudomonas spp. are important aetiological agents of neonatal infections in Brazil. There is a lack of data in the literature regarding the specific transport of immunoglobulin G (IgG) against these pathogens in multiple pregnancies. Maternal (n = 55) and umbilical cord (n = 110) blood samples were prospectively collected at birth from 55 twin pregnancies. The factors associated with cord levels and transfer ratios of IgG against GBS, Klebsiella and Pseudomonas were examined. The IgG umbilical cord serum levels specific to GBS, Klebsiella LPS and Pseudomonas LPS were significantly associated with maternal-specific IgG concentrations and the presence of diabetes. The anti-Klebsiella IgG cord serum concentrations were also related to birthweight and the presence of hypertension. The transfer ratios against GBS and Pseudomonas LPS were associated with maternal-specific IgG concentrations. The transfer ratios for GBS and Pseudomonas LPS were associated with gestational age at delivery and the presence of diabetes, respectively. None of the examined parameters were related to Klebsiella LPS transfer ratios. We conclude that in twin pregnancies, specific maternal IgG serum concentrations and diabetes were the parameters associated with umbilical cord serum IgG concentrations reactive with the three pathogens investigated. All the other parameters investigated showed different associations with neonatal-specific IgG levels according to the antigen studied. There was no uniformity of the investigated parameters regarding association with placental IgG transfer ratios against the GBS, Pseudomonas LPS and Klebsiella LPS.

Transplacental total IgG transfer in twin pregnancies.

PROBLEM: In twin pregnancies, factors that influence total umbilical cord IgG concentration and IgG transfer ratio are not well known. METHOD: Blood samples were prospectively collected from 57 twin pregnancies. Stepwise multivariate regression analysis was used to evaluate the association between total IgG levels in the umbilical cord blood and IgG transfer ratio according to serum IgG concentration, pregnancy chorionicity, the presence of abnormal umbilical artery pulsatility index, intrauterine growth restriction, gestational age at delivery (GAD), birthweight, and placental weight. RESULTS: Umbilical cord IgG concentration showed a positive correlation with serum IgG concentration and GAD; levels were significantly lower in monochorionic compared with dichorionic pregnancies. IgG transfer ratio also increased with GAD but was inversely correlated with serum IgG concentration levels. CONCLUSION: In twin pregnancies, besides serum IgG concentration and GAD, chorionicity also influences umbilical cord IgG concentration. Monochorionic twins have lower IgG cord concentration than dichorionic twins.

Peripartum cardiomyopathy: moving towards a more central role of genetics.

Peripartum cardiomyopathy (PCM) is a relatively rare disease with potentially devasting consequences requiring prompt identification and correct treatment. Overall prognosis is good in majority of the cases, although some patients may progress to irreversible heart failure. Early diagnosis is important and effective treatment reduces mortality rates and increases the chance of complete recovery of ventricular systolic function. The aetiology and pathogenesis seems to be multifactorial and poorly understood, with the available literature rather conflicting. In recent years, there has been increased interest in the role played by genetic predisposition in the development of PCM. It probably develops as a result of a complex interaction of pregnancy-associated factors and genetic factors and recently there have been many observations pointing out the central role played by a genetic predisposition. The direct and indirect observations on genetic susceptibility may offer new insights into the pathogenesis of PCM. However, larger studies are needed before advising routine genetic testing in these patients.

Maternal thyroid function at gestational weeks 11-13 in twin pregnancies.

BACKGROUND: Thyroid disease during pregnancy may be associated with increased risk of various pregnancy complications. It is known that serum thyrotropin (TSH) is suppressed because of the increased hormone production induced by human chorionic gonadotrophin (hCG) in early pregnancy, and that higher hCG levels in twin pregnancies may cause a more pronounced physiologic suppression. The recognition of this phenomenon is important in order to avoid unnecessary concerns and to correctly establish the diagnosis of overt thyroid disease in twin pregnancies. The aim of this study was to establish reference ranges of maternal serum TSH and free thyroxine (FT4) at gestational weeks 11-13 in twin pregnancies. METHODS: This is a case series of 177 dichorionic and 58 monochorionic twin pregnancies with normal outcomes, and 19 monochorionic pregnancies complicated by severe twin-twin transfusion syndrome. Maternal serum concentrations of TSH, FT4, antithyroperoxidase, and antithyroglobulin antibodies were measured at gestational weeks 11-13. The measured TSH and FT4 were converted to multiple of median (MoM) of normal singleton pregnancies and MoM values in the different groups were compared. RESULTS: In the antibody-negative twin pregnancies with normal outcomes, compared to singletons, serum TSH MoM was lower (median 0.62 [interquartile range [IQR 0.16-1.18] vs. 1.01 [IQR 0.61-1.51]; p < 0.0001), FT4 MoM was not significantly different (median 0.98 [IQR 0.91-1.08] vs. 0.99 [IQR 0.91-1.09]; p = 0.975), and free ß-hCG MoM was higher (median 1.91 [IQR 1.33-2.59] vs. 0.98 [IQR 0.66-1.50]; p < 0.0001). In the antibody-positive group (n = 37), compared to the negative group (n = 198), the median TSH was higher, but FT4 and free ß-hCG were not significantly different. In the twin-twin transfusion syndrome group, compared to normal twin pregnancies, TSH, FT4, and free ß-hCG were not significantly different. CONCLUSION: In twins, compared to singleton pregnancies, TSH is lower but FT4 is not significantly different. These reference ranges of thyroid hormones in twins can form the basis for the study of early thyroid function in pathological pregnancies and the investigation of the consequences of overt and subclinical hypothyroidism on twin pregnancy outcome.

Maternal IgM antibody status in confirmed fetal cytomegalovirus infection detected by sonographic signs.

OBJECTIVE: To evaluate the value of maternal IgM to cytomegalovirus (CMV) as a predictive factor of fetal infection in fetuses with sonographic markers. METHODS: Observational study (2006-2011) including a consecutive series of 19 fetuses with sonographic markers of fetal infection and confirmed infection by positive CMV-DNA in amniotic fluid or fetal blood. We evaluated the status of maternal CMV IgM at the time of sonographic suspicion. RESULTS: During this 6-year study period, CMV infection was diagnosed in 19 fetuses from 18 pregnancies, including 16 singletons, both twins of a monochorionic diamniotic pregnancy and one twin of a dichorionic pregnancy. Sonographic suspicion was established on the basis of one or more of the following: brain abnormalities (14), fetal hydrops (4), hyperechogenic bowel (4), pericardial effusion (1), cardiomegaly (1), oligoanhydramnios (4), and placentomegaly (2). Maternal IgG antibodies were positive in all cases but maternal IgM antibodies were negative in 56% of pregnancies. Five of the 10 pregnancies with negative maternal IgM were diagnosed in the second trimester and five in the third trimester. CONCLUSION: In around half of fetuses with confirmed CMV infection ascertained by sonographic markers, maternal IgM antibodies are negative and should therefore not be used as a diagnostic parameter.

Molecular Diagnostic Challenges and Complex Management of Consecutive Twin Pregnancies in a Family with CD40 Ligand Deficiency.

X-linked hyper-IgM syndrome (XHIGM) is a primary immunodeficiency disorder (PID) caused by mutation in the gene encoding the CD40 ligand (CD40L) expressed on activated T cells. Prenatal genotyping in carriers with twin pregnancies is more challenging than in women with singleton pregnancies. In addition, women with twin pregnancies may decide on selective termination for which the risk of loss of the healthy foetus may exceed 7%. We report here on a family affected by XHIGM. Diagnosis of the disease was made in a male patient as late as 33 years of age. After family screening, the sister of the proband conceived male twins in two consecutive pregnancies. In the first pregnancy, one of the male foetuses was hemizygous for the c.521A>G (Q174R) mutation in the CD40L gene. In the second pregnancy, ultrasound scan showed one foetus to have exencephaly and karyotyping revealed this foetus to have trisomy 18. Several options were discussed, but the parents decided on selective termination in both pregnancies. The interventions were successful in both cases, and the mother now has two healthy sons. This report demonstrates the way in which advanced technologies in molecular medicine and obstetric interventions may assist families with decisions about possible selective termination in case of life-threatening molecular or chromosomal disorders. Diagnosis of CD40L deficiency at the age of 33 years in the proband was striking and indicated that PIDs are still neglected as disease entities in the evaluation of patients with recurrent severe infectious diseases.